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Wu L.,Chinese Academy of Agricultural Sciences | Wu L.,Laboratory of Quality and Safety Risk Assessment for Cereal Products Beijing | Qiu L.,Chinese Academy of Agricultural Sciences | Zhang H.,Chinese Academy of Agricultural Sciences | And 7 more authors.
Toxins | Year: 2017

Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEN) are the most common contaminants in cereals worldwide, causing a wide range of adverse health effects on animals and humans. Many environmental factors can affect the production of these mycotoxins. Here, we have used response surface methodology (RSM) to optimize the Fusarium graminearum strain 29 culture conditions for maximal toxin production. Three factors, medium pH, incubation temperature and time, were optimized using a Box‐Behnken design (BBD). The optimized conditions for DON production were pH 4.91 and an incubation temperature of 23.75 °C for 28 days, while maximal ZEN production required pH 9.00 and an incubation temperature of 15.05 °C for 28 days. The maximum levels of DON and ZEN production were 2811.17 ng/mL and 23789.70 ng/mL, respectively. Considering the total level of DON and ZEN, desirable yields of the mycotoxins were still obtained with medium pH of 6.86, an incubation temperature of 17.76 °C and a time of 28 days. The corresponding experimental values, from the validation experiments, fitted well with these predictions. This suggests that RSM could be used to optimize Fusarium mycotoxin levels, which are further purified for use as potential mycotoxin standards. Furthermore, it shows that acidic pH is a determinant for DON production, while an alkaline environment and lower temperature (approximately 15 °C) are favorable for ZEN accumulation. After extraction, separation and purification processes, the isolated mycotoxins were obtained through a simple purification process, with desirable yields, and acceptable purity. The mycotoxins could be used as potential analytical standards or chemical reagents for routine analysis. © 2017 by the authors; licensee MDPI, Basel, Switzerland.


Lu M.,Chinese Academy of Sciences | Lu M.,Laboratory of Quality and Safety Risk Assessment for Cereal Products Beijing | Li W.,Chinese Academy of Sciences | Li W.,Laboratory of Quality and Safety Risk Assessment for Cereal Products Beijing | And 6 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2014

The heavy metals of arsenic and cadmium in cereals were measured by inductively coupled plasma mass spectrometry. By analyzing the determination process to find the uncertainy source, establish the mathematical model, combine and expand the single synthesis, the evaluation method of uncertainty was established. The results showed that the content of arsenic in cereals was (0.33 ± 0.026) mg/kg, K=2, and the content of cadmium was(0.16 ± 0.016) mg/kg, K=2. The main uncertainties were attributed to four sources, namely solution determination, measurement repeatability, sample dilution and sampling in decreasing order of uncertainty contribution.


Wu L.,Chinese Academy of Agricultural Sciences | Wu L.,Laboratory of Quality and Safety Risk Assessment for Cereal Products Beijing | Wang B.,Chinese Academy of Agricultural Sciences | Wang B.,Laboratory of Quality and Safety Risk Assessment for Cereal Products Beijing
Food Chemistry | Year: 2016

We hereby report the transformation of deoxynivalenol (DON) and its acetylated derivatives (3-ADON and 15-ADON) by spiking targeted mycotoxins to Fusarium mycotoxin-free flour in the process of making Chinese steamed bread (CSB). The impacts of pH, yeast level, and steaming time on the transformation of 3-ADON to DON were investigated. DON, 3-ADON, and 15-ADON were analyzed by UPLC-MS/MS. Spiked DON was stable throughout the CSB making process. Spiked 3-ADON and 15-ADON were partially deacetylated and transformed to DON during kneading (54.1-60.0% and 59.3-77.5%, respectively), fermentation (64.0-76.9% and 78.2-91.6%, respectively), and steaming (47.2-52.7% and 52.4-61.9%, respectively). The ADONs level increased after steaming compared with their level in the previous step. The pH level and steaming duration significantly (P < 0.05) affected the conversion of 3-ADON during the CSB making process. Briefly, alkaline conditions and short steaming times favored the deacetylation of 3-ADON. The level of yeast did not remarkably (P < 0.05) alter the transformation between ADONs and DON. © 2016 Elsevier Ltd. All rights reserved.


Wu L.,Laboratory of Quality and Safety Risk Assessment for Cereal Products Beijing | Wang B.,Chinese Academy of Agricultural Sciences
Food Chemistry | Year: 2015

The present study investigated the changes and conversion profiles of DON, its conjugations 3-ADON, and 15-ADON during bread making process, by spiking targeted mycotoxin standards to Fusarium mycotoxins-free wheat flour. No significant (p < 0.05) changes of DON levels were observed during dough preparation stages, including kneading, fermentation, and proofing. A reduction of DON level ranged from 4% to 14% was observed during baking process. The main thermal degradation products of DON, namely norDON A, B, C, and F were detected in the bread crust. Regarding ADONs, decreases of 20-40% for 3-ADON and 28-60% for 15-ADON were found during fermentation stage, and further losses of ADONs were observed after proofing process. Although ADONs levels gained an increase after baking. This study demonstrated that ADONs were converted to DON, while no ADONs were detectable in DON spiked samples during bread making process. The mechanism that ADONs could be converted into DON is unclear so far. © 2015 Published by Elsevier Ltd.

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